A typical photovoltaic module or solar cell comprises a plurality of individual components to harness solar energy while providing a durable and stable construction. For example, a photovoltaic module may comprise a backsheet, a bottom layer of encapsulant, a photovoltaic cell, a layer of encapsulant over the cell, and a transparent, rigid cover. The components are sandwiched together so light can pass through the upper layers of the module and impinge upon the cell. The cell converts the incident photons to electrons to harness the energy of the incident light. However, the overall efficiency of photovoltaic modules depends at least in part on the amount of incident light reaching the photovoltaic cells. Light may be absorbed, reflected or refracted by the plurality of components and interfaces in the module, thereby limiting the amount of incident light reaching the cell.
While each individual component serves a specific role, the encapsulant may be of particular importance to the cell's efficiency due to its many requirements. It must be optically transparent, electrically insulating, mechanically compliant, adherent to both glass and photovoltaic cells, and sufficiently robust to withstand an extended life in the field. There have already been various attempts to overcome disadvantages inherent in using different materials for the encapsulant. For example, traditional cells have often used ethylene vinyl acetate (EV A) copolymers as the encapsulant material. However, EVA is not stable when exposed to UV radiation. To improve long term stability, typically UV absorbers must be added, which results in the encapsulant having low light transmission in the UV range of the spectrum. It has been proposed to replace EVA with silicones as the encapsulant because silicones are stable over a wide range of temperatures, have desirable dielectric properties, and possess optical transparency.
However, there remains a need in the art to continue to improve upon the efficiency of photovoltaic modules and arrays.